Debugging
Debugging is how ABAP developers find and fix problems by stepping through code and inspecting data at runtime. The ABAP debugger is powerful, and skilled debugging is one of the most valuable practical abilities.
The debugger can change data, so use it carefully, especially in production (where debug/change authorization is tightly controlled).
- You start the debugger by setting a breakpoint (in the editor, or /h in the command field before running a transaction).
- A key skill is knowing where to break.
- Breakpoints: line, and powerful conditional/statement/exception breakpoints (e.g. break when a specific message is issued or an…
- Watch out: Stepping blindly instead of breaking on the message/exception.
The ABAP debugger
You start the debugger by setting a breakpoint (in the editor, or /h in the command field before running a transaction). It then lets you step through the code line by line, watch variables and internal tables, inspect the call stack, and even change values on the fly to test scenarios.
Debugging techniques
- Breakpoints: line, and powerful conditional/statement/exception breakpoints (e.g. break when a specific message is issued or an exception is raised).
- Watchpoints: break when a variable’s value changes.
- Step / step over / return: control execution granularity.
- Layers: debug across RFC and background steps.
Finding the right place to break
A key skill is knowing where to break. Techniques include setting a breakpoint on a message (to catch where an error is raised), on an exception class, or on a statement like a specific function call. This gets you to the problem without stepping through thousands of lines.
Debugging responsibly
The debugger can change data, so use it carefully, especially in production (where debug/change authorization is tightly controlled). Non-production is the place to experiment. Reading dumps (ST22) often complements debugging by showing exactly where and why code failed.
Common pitfalls
- Stepping blindly instead of breaking on the message/exception.
- Changing values in production, tightly controlled for good reason.
- Ignoring ST22 dumps that pinpoint failures.